Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Nikon S6100 and Panasonic GF5 side-by-side from the front, back and top in their relative dimensions. Nikon S6100 has external dimensions of 98 x 58 x 27 mm (3.86 x 2.28 x 1.06″) and weighs 175 g (0.39 lb / 6.17 oz) (including batteries). Panasonic GF5 has external dimensions of 108 x 67 x 37 mm (4.25 x 2.64 x 1.46″) and weighs 267 g (0.59 lb / 9.42 oz) (including batteries).
Below you can see the front-view size comparison of the Nikon S6100 and the Panasonic GF5. Nikon S6100 is clearly the smaller of the two cameras. Its body is 10mm narrower, 9mm shorter and 10mm thinner than Panasonic GF5. As you can tell, actually this is not a fair size comparison since Nikon S6100 has a built-in lens but Panasonic GF5 doesn't. Once you put a lens on GF5, its thickness will increase significantly.
Now lets look at the top view comparison of Nikon S6100 and Panasonic GF5.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Nikon S6100 is significantly lighter (92g ) than the Panasonic GF5 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on GF5, the total kit will weigh much higher.
Weather Sealing
Unfortunately neither the Nikon Coolpix S6100 nor Panasonic Lumix DMC-GF5 provides any type of weather sealing in their bodies, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Nikon S6100 and Panasonic GF5's LCD screens have the same diagonal size of 3.00 inches.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.